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Silk fibroin (SF) is a natural protein, which is derived from the Bombyx mori silkworm. SF based porous materials are extensively investigated for biomedical applications, due to their biocompatibility and biodegradability. In this work, CO2 assisted acidification is used to synthesize SF hydrogels that are subsequently converted to SF aerogels. The aqueous silk fibroin concentration is used to tune the morphology and textural properties of the SF aerogels. As the aqueous fibroin concentration increases from 2 to 6 wt%, the surface area of the resultant SF aerogels increases from 260 to 308 m(2) g(-1) and the compressive modulus of the SF aerogels increases from 19.5 to 174 kPa. To elucidate the effect of the freezing rate on the morphological and textural properties, SF cryogels are synthesized in this study. The surface area of the SF aerogels obtained from supercritical CO2 drying is approximately five times larger than the surface area of SF cryogels. SF aerogels exhibit distinct pore morphology compared to the SF cryogels. In vitro cell culture studies with human foreskin fibroblast cells demonstrate the cytocompatibility of the silk fibroin aerogel scaffolds and presence of cells within the aerogel scaffolds. The SF aerogels scaffolds created in this study with tailorable properties have potential for applications in tissue engineering.

A green synthesis method for the preparation of polyglycidol in buffer with a high degree of control is presented. Polymerizations were conducted in phosphate buffered saline (PBS) of varying pH 3.8, 6.0, and 8.0 and deionized water at temperatures of 60, 80, and 100 °C. Taking advantage of the catalytic reactivity between water and glycidol afforded a novel green polymerization technique for the facile synthesis of polyglycidol systems with semibranched architectures with a degree of branching (DB) of 0.24, which situates the polymers between purely linear (DB = 0) and hyperbranched (DB = 0.56–0.63) systems. This method sidesteps the strenuous polymerization conditions required for most polyglycidol structures and provides well-controlled and reproducible species with a high degree of linearity and narrow polydispersities of 1.1–1.2 via the first green and nonexothermic synthesis of polyglycidol.